It is Day 100 in President Obama’s second term, not the milestone moment it was in the first term, but still an opportunity for stock-taking.

In a hastily called press conference Tuesday morning, Mr. Obama laughed at a reporter’s suggestion that he may not have the “juice” to get the rest of his agenda through a divided Congress, after the defeat of a gun-control measure that had strong public backing and the president’s vocal support.

“Maybe I should just pack up and go home,” the president joked, speaking in the White House briefing room. “As Mark Twain said, you know, rumors of my demise may be a little exaggerated at this point.”

What a difference a few days, and a wholly different context, make. At last Saturday night’s black-tie White House Correspondents’ Dinner, Obama stepped to the podium to the rap tune “All I Do Is Win” and said, “Rush Limbaugh warned you about this – second term, baby.”

The reality, of course, is somewhere in between. Each issue on the table has its own political dynamic. Obama expressed confidence that “a range of things” will get done, despite the “dysfunction” on Capitol Hill.

“I feel confident that the bipartisan work that's been done on immigration reform will result in a bill that passes the Senate and passes the House and gets on my desk,” the president said.

Obama also voiced caution over how the United States would proceed on Syria, given the recent signs that chemical weapons had been used in that nation’s civil war.

“We now have evidence that chemical weapons have been used inside of Syria,” the president said. “But we don’t know when they were used, how they were used, or who used them.... If we end up rushing to judgment without hard, effective evidence, then we can find ourselves where we can’t mobilize the international community to support what we do."

“Based on what I've seen so far, the FBI performed its duties; Department of Homeland Security did what it was supposed to be doing,” Obama said. “But this is hard stuff.”

Obama was responding to a question about a report that the director of national intelligence, James Clapper, has ordered a broad review of all the intelligence-gathering before the April 15 attack.

The president called Mr. Clapper’s review “standard procedure,” saying that whenever there’s an incident, the government reviews all the steps taken beforehand and determines if any lessons can be learned.

“One of the dangers that we now face are self-radicalized individuals who are already here in the United States, in some cases may not be part of any kind of network, but because of whatever warped, twisted ideas they may have, may decide to carry out an attack,” Obama said. “And those are in some way more difficult to prevent.”

Still, he said, he has asked his counterterrorism team to see what more can be done to engage with “communities where there's a potential for self-radicalization of this sort.”

The president took questions for only 48 minutes, less than the usual hour he devotes to press conferences. And he only called on TV reporters, except for Antonieta Cadiz of impreMedia, a Hispanic newspaper chain. On Thursday, Obama heads to Mexico and then Costa Rica.

But he did break from his usual practice of ignoring shouted questions as he leaves the room, when he responded to one about Jason Collins, the National Basketball Association player who announced Monday that he is gay and whom Obama called to congratulate. The president returned to the podium, and delivered effusive praise for Mr. Collins.

“You know, given the importance of sports in our society,” Obama said, “for an individual who's excelled at the highest levels in one of the major sports to go ahead and say, ‘This is who I am. I'm proud of it; I'm still a great competitor. I'm still seven feet tall and can bang with Shaq and, you know, deliver a hard foul’ – and for a lot of young people out there who are gay or lesbian, who are struggling with these issues, to see a role model like that who’s unafraid, I think it’s a great thing.”